Homework Sourse1 Choose the best response for each a The Ames test is commo
1.) Choose the best response for each.
a.) The Ames test is commonly used to test whether a particular chemical is mutagenic. When you conduct an Ames test, you need two groups of plates. One group of plates contains bacteria that are exposed to the chemical of interest, while the other plates contain bacteria that are not exposed to the chemical. Why is the latter group needed if you are just interested in the rate of mutation caused by the chemical?
b.) Frameshift mutations can be very severe. What is one reason why they are often so serious?
c.) An organism that cannot synthesize methionine is called __________.
| The group without the chemical can be exposed to mammalian liver extract to see the effects of liver enzymes on the bacteria. |
| Having two groups allows researchers to compare the effects of different environments on the mutation rate |
| It is important to compare the rate of mutations with the chemical to the normal background mutation rate. Mutations occur spontaneously even without the presence of a mutagen. |
| The second group is used as a control to make sure that the replica plating technique is done correctly. |
Solution
1.A. C. Mutation also occur spontaneously even without a mutagen. So, in Ames test they use two plates one with Mutagen and other with no mutagen and compare the mutation with natural background.
Replica plating is used to screen for a desired phenotypes or comparision of antibibiotic resistant bacteria. It generally used for negative selection.
Mammalian liver extract may be used in Ames test, if experimenter try to analyze any mutagen cause any mutation in mammaliain cell.
1.B. B Frame shift mutation is addition or deletion of group of base pairs. It directly affects the translational reading frame. Reading frame present in the downstream of the gene So, this mutation changes the amino acids sequence present in the downstream.
Transition mutation is a single base bair or point mutation. Purine is mutated to another purine.
1.C Auxotroph
Mutant - A organisms undergoes a mutation
Prototroph - A organism synthesize their own food by inorganic substances .
Auxotroph - A organism unable to synthesize a particular compound for their growth and surive.
Autotroph- A organism synthesize their own food by light source .
